I'm not mixing stable and testing. All testing except I'm using google chrome unstable downloaded as a deb from google dev channel. Google adds itself to the sources automatically and a recent update to it lists stable, beta and unstable to the stable source in the list on left.

stevepusser wrote:I can't really see any duplicates; can you point them out?

What is your compelling reason for mixing stable and testing repositories, which should only be done by experts?

(hoping that this install hasn't become the dumpster fire that this kind of sources.list can become...)

Unless the image was changed or something since your post, how about the four 0ad-data and 0ad-data-common 0.0.21-1 entries?

Would be interesting to see what exactly apt-cache policy would spit out for 0ad-data, maybe it is debu[1-9] versions that just haven't left the repo yet? That's where I would look first, see what the APT system itself is showing.

fortune -o Your love life will be... interesting. How did it know?

The U.S. uses the metric system too, we have tenths, hundredths and thousandths of inches

Lots of other examples but only when viewing packages that have not yet been installed under Origin.Do you think the duplicates are due to multi-architecture? (amd64 + i386)But Synaptic does not differentiate the architectures.

TonyT wrote:Is this a bug in Synaptic? If so, how to fix?Debian Stretch.Synaptic lists duplicate entries but only when selecting Origin (not yet installed).

Does your system behave differently if you comment out the repository in your sources that is not an official one, http://www.deb-multimedia.org? [EDIT] Of course, then update (reload the package lists).

Christian Marillat's multimedia repository isn't an Official Debian repository, it was always a third-party repository that in the past was useful but generally not needed as often today and probably should only be used by people who know that they need it and why.

TonyT wrote:Lots of other examples but only when viewing packages that have not yet been installed under Origin.Do you think the duplicates are due to multi-architecture? (amd64 + i386)But Synaptic does not differentiate the architectures.

Yes, I think this is the cause of the problem. My suggestion would be to not use Synaptic (despite how easy it makes to install software, learn to use the command-line, it'll never fail you) and instead use apt to install packages since this will save you the problem of installing an i386 package on an amd64 machine (not a problem per se but it does cause needless duplication). You can use apt install package:arch if you want to install the package for a particular architecture.

If you think you've added an arch by mistake then you can remove it like this (don't do this if you have installed packages for that architecture):

The source code for the kernel, library, etc. should fit on one diskette. Sources for the GNU utilities will vary (and will be big). The sources to GNU emacs will take at least 3 disks. -- Theodore Ts'o, 1992 (distributing the first Linux disks)

I booted up a VM running Jessie AMD64. Synaptic is not showing any duplicates. So I added the i386 architecture and updated. Still no duplicates. So I added the contrib & non-free sections, and updated. Still no duplicates.